1. Field of the Invention
The apparatus of the present invention relates to air flow controllers, and more particularly to air flow controllers suited for use in solar energy heating systems.
2. Description of the Prior Art
As the attractiveness of solar heating is recognized as a pollution free and inexhaustible source of energy, numerous attempts have been made to efficiently harness the energy available. At the present time the most viable method involves using a heat collector to accumulate energy from the sun. The collector is connected to both the building to be heated and a storage unit, such as an enclosure containing rock buried under the ground.
There has been very little development in the area of solar controllers for controlling the flow of heat between the storage, collecting and use areas. An example of such a unit, however, is described in U.S. Pat. No. 4,129,116 to T. B. Kent.
Most prior art controllers utilize pivotal plates to control air flow. Due to configuration problems, these flat plates must be ganged in pairs through a linkage arrangement in order to provide two passageways through a given chamber of a controller. Not only is a linkage necessary, but a biasing of the plate that is not powered is also required. More moving parts means, quite simply, less reliability and more operational maintenance.
Aerodynamic forces resulting from both positive and negative forces from the blower, do affect controls. Lower pressures have a tendency to create lift on the control surface on the side exposed to the lower pressure. If the plate then "floats" from its closed position, the lower pressure created by flow across the surface helps draw air from a cooler location with a resultant lowering of efficiency.
Prior art controls are also heavily effected by their own weight. This gravity factor can enhance "floating" controls and further limits the orientation controls may have within a controller system. Therefore, an axis of rotation for controls has always been perpendicular to the surface of the earth, and no moments of rotation are created by gravitational forces. Horizontal orientation for controls was therefore unavailable in the prior art because a horizontal plane would increase gravitational effects. This results in control units that must be aligned in only one plane for best effect.